In this article, we incoporate a novel query language which is used to retrieve data via this new query language on key-value NoSQL, such as MongoDB. Recently, NoSQL has drawn more attention on it, espcially in internet corporations… See More:[Read More…]
In this article, A novel mechanism of transfering query statements between sql and xquery. A novel tool is introduced to translate the sql statement to xquery, or via vers. By this way, we can easily translate the sql to xquery or transf it back. [Read More…]
In this article, I wil give out a way of how to design a new query engine step by step. Going insight and going out to see who many aspects will involved in designing a new query engine. Including xml files parser, and lexcial and grammar parser, query optimizor, executor,… See More:[Read More…]
In this article, I will present the ways of using indices in XMLDB. Considering the existed codes, the XMLDB misses a lots of codes to use the indices properly. So that if some ways are needed to introduc to XMLD. In the article, the rule-based optimization and cost-based optimization, etc. are introduced.[Read More…]
In this article, I will present the ways of storing the data in PostgreSQL. Including the format of a tuple and how the PostgreSQL stores the data into the magnetic disk and how to orginze the data on magnetic disk. Notes: this article is written when i read the PostgreSQL source code, the storage Engine code as a note on reading, and this will be moved to an apporiate place in which i will talk it in deep lately. [Read More…] and [Read More…]
In this article, I will present the ways of using the statistic data in PostgreSQL. In planning phrase of otpimization, the PostgreSQL will choose the cheapest path as the best execution path, so how to evaluate all of the choices, and get the best one? In this article, i will give out a brief disscution on that. [Read More…].
In this article, I will present the basic concept of cache and its Cache-coherent protcol-MESI. The tansition diagram will be discussed in detail. Each status will be given the deep explanation to help the reader to understand the protocol.[Read More…].
In this article, I will present the basic concept of executing nested queries which is orignated from Goetz Graefe’s Paper —“Executing Nested Queries”. In this paper, Graefe discussed how to improve the performance of executing nested queries and also giving out the means of performance-improvement of nested queries. Including asychronous IO, caching, etc. [Read More…].
In this article, We introduce some basic ideas of using SIMD instruction to enhance the EE operators’ performance. By employing the SIMD tech, we can perform the operators in parall mode so that a gaint performance raised.[Read More…].